title: Microparticles as a strategy for low-molecular-weight heparin delivery.
abstract: The aims of this work were preparation and physical-chemical characterization of a microparticulate release system for delivery of enoxaparin sodium (ENX), a low-molecular-weight heparin, as a potential vehicle for optimization of deep venous thrombosis therapy. Microparticles (MPs) containing ENX were prepared from polylactide-co-glycolic acid [PLGA; (50:50)] by a double emulsification/solvent evaporation method. The preparation parameters, such as proportion ENX/PLGA, surfactant concentration, type, time, and speed of stirring, were evaluated. The encapsulation efficiency and yield process were determined and optimized, and the in vitro release profile was analysed at 35 days. The MPs showed a spherical shape with smooth and regular surfaces. The size distribution showed a unimodal profile with an average size of 2.0 ± 0.9 μ m. The low encapsulation efficiency (<30%), characteristic of hydrophilic macromolecules was improved, reaching 50.2% with a procedure yield of 71.3%. The in vitro profile of ENX release from the MPs was evaluated and showed pseudo-zero-order kinetics. This indicated that diffusion was the main drug release mechanism.
authors.affiliation: Laboratório de Tecnologia Farmacêutica; Laboratório de Controle de Qualidade de Produtos Farmacêuticos e Cosméticos - Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Av. do Café s/n. 14040-903 Ribeirão Preto, São Paulo, Brazil.
authors.forename: Samantha S M
authors.initials: SS
authors.lastname: Oliveira
authors.forename: Fabiana S
authors.initials: FS
authors.lastname: Oliveira
authors.forename: Cristiane M
authors.initials: CM
authors.lastname: Gaitani
authors.forename: Juliana M
authors.initials: JM
authors.lastname: Marchetti
mesh_terms: D000925:Anticoagulants / Q000008:administration & dosage*; D002214:Capsules / Q000737:chemistry*; D003692:Delayed-Action Preparations / Q000737:chemistry; D004339:Drug Compounding / Q000379:methods; D017984:Enoxaparin / Q000008:administration & dosage*; D006801:Humans; D019344:Lactic Acid / Q000737:chemistry; D010316:Particle Size; D011100:Polyglycolic Acid / Q000737:chemistry; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D020246:Venous Thrombosis / Q000188:drug therapy
chemical_list: D000925:Anticoagulants; D002214:Capsules; D003692:Delayed-Action Preparations; D017984:Enoxaparin; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid